1. Field of the Invention
This invention relates to unleaded aviation gasolines. More specifically, this invention is directed to an unleaded aviation gasoline possessing a high motor octane number for use in piston driven aircraft which require high octane fuels.
2. Background of the Invention
The high octane requirements of aviation gas for use in piston driven aircraft which operate under severe requirements, e.g., aircraft containing turbo charged piston engines require that commercial aviation fuels contain a high performance octane booster. The octane boosters for automobile gasolines (Mogas) such as benzene, toluene, xylene, methyl tertiary butyl ether, ethanol and the like are not capable by themselves of boosting the motor octane number (MON) to the 98 to 100 MON levels required for aviation gasolines (Avgas). Tetraethyl lead is therefore a necessary component in high octane Avgas as an octane booster. However, environmental concerns over lead and its compounds may require the phasing out of lead in Avgas.
U.S. Pat. No. 2,819,953 describes aromatic amines added to motor gasolines as antiknock agents. However, motor gasolines have much lower octane requirements than aviation gasolines for piston driven aircraft. One cannot predict performance of a given antiknock agent in an aviation gasoline based on its performance as an antiknock agent in a motor gasoline.
It would be desirable to find a non-lead based octane booster for Avgas which will permit formulation of a high octane Avgas.